Wondering if anyone else out there is finding they have to replace PTFE tubes A LOT with the H2C. Granted I understand that the amount of friction caused by the huge number of color changes is going to cause wear, but it just seems like I’m doing this way more often than I expected. And this is both internal AMS tubes (including both the AMS 2 Pros and HTs). It’s cheap and generally easy to replace them (the internal HT tube is a BIT of a pain but not horrible), but if there’s a better way I’m all ears!!
What materials are you using?
What is your decision criteria for determining when you need to change your PTFE?
And could you quantify “A LOT” a bit more specifically? 10s of hours, 100s, thousands?
My experience is very different:
1,888h on my H2C with 2AMS2, 1 HT: Printing PLA, PLA Wood, PETG, PETG-CF so far: The only thing I replaced so far is a single Vortek nozzle. Not using slot 3 of one of the AMS2’s though for multi-filament prints though as I’d have to replace that PTFE though 
Cut too short and non-perpendicular at factory.
From my X1C, I consider myself a PTFE torture test. 5,401h with 2 AMS1 (one with 5,401h, the other ~7,100h): Replaced the toolhead PTFE twice, main path & all AMS internal PTFE’s for the older unit once.
My own criteria are rather lax:
- When feed issues arise due to worn PTFE coupler-interfaces or
- The filament is literally poking me in the eye
So it’d be interesting to know what it is that makes you change your PTFE’s. Or if there may be other root causes (I had a broken PTFE-coupler on my X1 once for example).
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Mostly pla. Occasional petg.
Literally when the get holes and the filament pokes through!
The angle the tube is bent though matters; a slightly longer tube, perhaps with a support bracket, can lessen the angle.
I would say mor towards a few hundred or less in some cases. Granted I print a lot of multicolor and I get it’ll wear down sooner, but I didn’t think it would be as soon as it is.
That is quite frequent. I"d expect there to be spots on the PTFE where you have increased wear compared to others.
- Did you notice “preferred” PTFE’s and locations?
- Do you use Bambu PTFE’s? Third party PTFE’s come in a variety of inner diameters. Thicker wall => More friction, thinner wall => less wear.resistance and more bending or even kinking
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I think I’ve had to replace most of the tubes but the biggest repeat offender is the internal tubes in the HT’s. Those are all Bambu tubes. The filament tears through an just winds up being pushed inside the cabinet…no choice but to replace!
How does the end of the filament looks like after it’s cut and retracted?
A poor filament cutter could leave a burr on the tip of the filament scratching the tube on every load cycle.
Short bends as @Eponymous already mentioned has a large impact also.
But the tubes in the AMS itself don’t have sharp bends. So are the AMS tubes worn out too, or do you just replace them because other tubes have worn out?